Photonics Dictionary: C

An imaging process in which the single opening of a simple pinhole camera is replaced with many openings called, collectively, the aperture. The recorded picture, which consists of many overlapping...

A reticle carrying patterns of various forms that can be rotated in an optical beam to cause variations in the intensity of the beam. It also is used in infrared detectors to scan the object field...

A fiber optic communications system that works on the principles of homodyning or heterodyning. The transmitting laser produces an optical wave that is modulated in amplitude, phase or frequency by...

A coherent fiber bundle (CFB), also known as a coherent fiber optic bundle, is an assembly of multiple optical fibers arranged in a specific geometric pattern to maintain the spatial coherence of...

An optical instrument used to determine the distance to a target being viewed. Two similar optical systems view the target via 45° mirrors at the ends of a fixed baseline. One system creates the...

1. The process of aligning the optical axes of optical systems to the reference mechanical axes or surfaces of an instrument. 2. The adjustment of two or more optical axes with respect to each other....

An optical instrument consisting of a well- corrected objective lens or mirror with a light source and or object/image (i.e. illuminated slit or retical) at its focal plane. Collimators are used to...

Certain color centers in the alkali halides have been optically pumped to produce efficient tunable pulsed and continuous-wave (CW) lasers emitting in the range of 0.8 to 3.3 µm.

A color center, in the context of materials science and condensed matter physics, refers to a specific type of crystallographic defect in a crystalline structure that introduces color to the...

A semitransparent mirror in an optical system that combines two or more output beams into a single coaxial beam.

The maximum rate at which temporally disjunct optical signals can be produced or detected.

An optical element that measures the phase difference between two components of elliptically polarized light to correct for mechanical or optical displacement.

1. A constituent part. It may consist of two or more parts cemented together, or with near and approximately matching surfaces. 2. The projection of a vector on a certain coordinate axis or along a...

A lens composed of two or more separate elements of optical glass that may or may not be cemented together. The surfaces of the elements are shaped to reduce or eliminate the aberrations inherent in...

A center-opening shutter made up of several identical leaves that are mounted symmetrically around the optical axis of the lens.

A method of producing large volumes of plastic optical components in which powdered or sheet plastic is pressed between heated dies.

Computer vision enables computers to interpret and make decisions based on visual data, such as images and videos. It involves the development of algorithms, techniques, and systems that enable...

The use of computer analysis in the calculation of diffraction patterns for information on the design of optical systems. In this method, the electric field amplitude and phase in the aperture are...

A computer-generated hologram (CGH) is a holographic image produced using computational methods and algorithms, rather than traditional optical techniques. CGHs are generated entirely in digital form...

The process of linking optical fiber end to end.

Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In the context of geometry or optics, a concave shape is one that curves or...

Concave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These mirrors are commonly used in optics for various applications, including...

The distance between the center of the two concentric circles of an optical fiber that designate the diameter of the cladding and the center of the two concentric circles that designate the diameter...

A confocal resonator, also known as a confocal cavity or confocal laser resonator, is a type of optical resonator configuration used in laser systems. The term confocal in this context refers to the...

Energy loss encountered at connectors in optical fiber transmission systems. The major contributors are mutual core displacement and fiber axis tilt. It is observed in both permanent splices and...

An optical instrument, generally a polarizing microscope, that is used to determine the interference figures and optical axis of a sample crystal. Also called a hodoscope.

The principle that states that optical instrumentation cannot increase the radiance of a source; the radiance of an image cannot exceed that of the object.

That property of certain optical devices, e.g., a penta prism, that maintains the angular relationship between the entering and the emerging rays traversing the system regardless of the orientation...

Method of disk rotation used for optical disk drives, in which the spindle motor decreases the speed of the disk's rotation as the head moves from the inner tracks to the outer, so that the radial...

Reciprocal of the dispersive power of an optical material. See Abbe constant.

Also called color blocking. The formation of a block by making optical contact between a number of optical elements and a large optical flat.

The radiography of small objects having detail too fine to be seen by the unaided eye. The resulting negative, when optically enlarged, can be examined.

In optical character recognition systems, the identification of a character facilitated by means of known factors governing its appearance in a particular context; e.g., the first character in the...

A method in optical character recognition in which a mobile light beam scans the outlines of characters for subsequent reading of these outlines.

The curved boundary between two optical media of different refractive indices, which causes convergence.

Convex is an adjective used to describe a surface or shape that curves outward, bulges, or has a rounded and outwardly extending appearance. In the context of geometry or optics, a convex shape is...

A camera mounted on an optical bench with an easel to hold the material to be copied. Magnification can be varied over a wide range by sliding the camera and easel.

A threadlike inclusion within a blank of optical glass. Rarely found in quality optical materials.

The light-conducting portion of an optical fiber, defined by the region of high refractive index.

A semispherical or conical lens created directly on the core of an optical fiber to focus light from a laser into the fiber core.

A corner cube, also known as a corner reflector or retroreflector prism, is a type of optical device used to reflect light or electromagnetic waves back towards their source with minimal deviation in...